Wobble drive



IJune 14, 1960 Filed Dec. 19, 1956 WIM P. BELZNER 2,940,324

WOBBLE DRIVE 2 Sheets-Sheet 2 ATTORNEY WOBBLE DRIVE Paul Belzner,Muhlacker, Germany, assignor to Schmid & Wezel, Mauibronn, Wurttemberg,Germany Filed Dec. 19, 1956, Ser. No. 629,362

Claims priority, application Germany Dec. 21, 1955 2 Claims. (Cl.74--60) The present invention relates to drives for converting rotarymotion into reciprocating motion.

More particularly, the present invention relates to a wobble driveadapted to be used in hand tools, for example, for converting the rotarymotion of a drive shaft into reciprocating motion of a driven shaft.

One of the objects of the present invention is to provide a wobble driveof the above type which is of a simple, compact construction and whichdoes not include any eccentrically driven elements.

Another object of the present invention is to provide a drive of theabove type which runs smoothly and easily and which will not bind.

A further object of the present invention is to provide a hand tool ofthe above type which can be comfortably handled and carried by theoperator during operation of the hand tool.

With the above objects in View, the present invention mainly consists ofa wobble drive for converting rotar-y motion into reciprocating linearmotion, this drive including a support means and a drive shaft supportedfor rotation about its axis by the support means. A driven shaft issupported for reciprocation along its axis by the support means. Awobble spindle is connected by a suitable means to the drive shaft fortilting movement about a point in the axis ofthe drive shaft duringrotation of the latter. A ball and socket joint is fixed to the drivenshaft and includes a ball member formed with a bore, and a lever meansis fixed to the wobble spindle and has a free end portion extendingslidably into the bore of the ball member of the ball and socket joint,so that a tool or the like carried by the driven shaft will reciprocatetherewith during rotation of the drive shaft.

The novel features which are considered as characteristic for theinvention are set forth in particular in the appended claims. Theinvention itself, however, both as to its construction and its method ofoperation, together with additional objects and advantages thereof, willbe best understood from the following description of specificembodiments when read in connection with the accompanying drawing inwhich:

Fig. 1 is a sectional elevational view of a hand tool according to thepresent invention, the wobble drive being shown in Fig. 1 in neutralposition where the driven shaft will not reciprocate during rotation ofthe drive shaft;

Fig. 2 is a sectional view of an adjusting means of the wobble drive,Fig. 2 being taken along line 2-2 of Fig. l in the direction of thearrow;

Fig. 3 is a schematic illustration of the operation of the wobble driveof the present invention; and

Figs. 4 and 5 are sectional elevational views, similar to Fig. 1, andshowing the wobble drive in tiited position.

The structure shown in Fig. 1 includes a support means in the form of ahousing 1, 2 which is relatively heavy. The portion 2 of the housingcarries ball bearings which support a drive shaft 3 for rotation aboutits axis, and the bottom end of this drive shaft, as viewed in Fig. 1,is connited States Patent Of Patented June 14, 1960 ice nected in anysuitable way to an unillustrated motor which rotates the drive shaft.The top end of the drive shaft 3, as viewed in Fig. 1, xedly carries ahead member 4, which is of bell-shaped coniiguration and which is openat its top end, as viewed in Fig. 1, the head member 4 thus rotatingwith the drive shaft 3.

The drive of the invention includes a wobble spindle 7 which is coaxialwith the drive shaft 3 in the position of the parts shown in Fig. l, andthis spindle 7' is carried by a bearing means 5 provided with ball orroller bearings 6 which interconnect the spindle 7 with the bearingmeans 5 in a manner enabling the bearing means to rotate about the axisof the spindle 7. The bearing means 5 includes a pair of opposed pins 17(Fig. 2) which respectively extend into opposed openings of the headmember 4 so that the bearing means 5 is in this way connected to thehead member 4 for turning movement about the common axis of the pins 17.It will be noted that this axis of the pins 17 is normal to the axis ofdrive shaft 3 and intersects the drive shaft axis at point a. Thus, thebearing means 5 can only turn with respect to the head member 4 about anaxis which is at all times perpendicular to the drive shaft axis and thewobble spindle axis and which intersects th drive shaft axis at point a.Y Y

An adjusting means is provided to set the angle of the :bearing means 5with respect to the head member 4, as

for instance shown in Figs. 4 and 5, and the details of this adjustingmeans are illustrated in Figs. l and 2. This adjusting means includes anut in the form of an elongated internally threaded tube 12, and -thistube 12 xedly car'- ries a pair of coaxial, opposed, lateral pins whichin turn carry annular bearing members 13. The bearing means 5 is formedwith a bottom elongated cutout which extends to the right and left, asviewed in Fig. l and which re- Vceives the nut 12 in the mannerindicated in Figs. 1 and 2,

and the side wall portions of the bearing means 5, which result from thebottom elongated cutout thereof, are respectively formed with alignedcutouts which are open at the bottom and which respectively receive thebearings 13. Arscrew 11 threadedly carries the nut 12 and extendsthrough opposed openings of the head member 4, as shown in Fig. l, andthis screw 11 is restrained against axial movement so that when thescrew 11 is turned the nut 12 will move `axially therealong to set thebearing means 5 at a preselected angle which will determine the strokeof the driven shaft described below. The screw 11 may carry a nut at itsright free end, as viewed in Fig. l, which may -be tightened to preventturning of the screw 11 after the angular position ofthe bearing means 5is adjusted. The housing portions 1 and 2 are removably connected t0each other by suitable screws or the like, so that these housingportions may be separated to give access to the adjusting screw 11. Whenthe housing portions 1 and 2 are separated from each other, the entiredrive is carried by the housing portion 2, the tool 19 beingdisconnected from the driven shaft 9 and the latter simply slipping outof open- -ings of the housing portion 1 when the latter and the housingportion 2 are separated from each other and the hand tool is reassembledwith the reverse of this procedure. If desired, the housing portions 1and 2 may be permanently connected to each other, and access to theadjusting screw 11 may be provided through an opening of the housingportion 1 which can be covered by a plate removably connected to thehousing portion 1. Instead of two sets of ball or roller bearing members6, as shown in Fig. l, a single set may be provided.

The driven shaft 9 is slidablj,l supported in suitable openings of thehousing portion i for reciprocating movement in a direction parallel tothe axis of the drive shaft 3. The bottom free end portion of the drivenshaft 9 which is located within the housing portion 1 xedly carries asocket member of a ball and socket joint which includes the ball member8. This ball member 8v is formed with a bore extending along a diameterof the ball member. v

1 Y1A levermeans 7 interconnects the wobble spindle 7' Ywith the VballVmember 8, and the lever means 7 has a configuration which locates thecenter b of ball member 8 in a straight line which is at all timesperpendicular totheaxis' of the wobble spindle' and which passes throughthe point a. This lever..meansV 7V yincludes Va i substantially L-shapedmember one leg of which is xed to the wobble spindle 7' and the Votherleg ofwhich is vfixed to a pin which extends through a rcutout f thersocket ofthe ball and socket joint slidably into the bore of the ballVmember 8. The cutout of the socket member is large enough to preventrubbing of the pin of lever means `7 which extends into the bore of ballmember 8 against the socket member during operation of theV drive.During reciprocation ofthe driven shaft 9, this pin slides zback andforth into the bore of the ball'member 8. In this way all'binding isveliminated with the structure of the invention. Itis apparent that whenthe parts have the-position'shown in Eig. 1, the shaft 9 will not recip-Y Vrocate during rotation of'the drive shaft 3, whilethe extentofreciprocation of the shaft 9 will` depend upon ,the angular positionof bearing means Swith respectto V thecornnion axis of, pins 17, thisangular position being set by turning the screw 11.

Any suitable tool such as a scraper blade 10 is remov-V Y ably iixed tothe driven shaft 9 for Vrec-iprocation there- Y amasarv v .withrespectto theA axisof drive shaft' and which serves as` a hand grip enablingthe operator tosecurely hold y,and easilyrguide the tool. In order toprevent slipping of the hand'of the'operator with respect to theYhousing 1, an elongated flexible band 14 of leather or the like isfixed to the housing 1 and formsa loop passing over thebulging portion15 so that the hand of the operator when it engages the bulging portiony15 will be securely located between the'housing portion 1 and the band14. Any suitable buckle or the like ymay be provided on the `band 14 toform a means for adjusting the length thereof. The drive shaft 3 may bedriven by any suitable electric motor, such as a universal motor, arotating eld motor, a high frequency motor, or an air driven motor maybe used. Also, a suitable gear transmission may be located between themotor and the shafty 3 for rotating figuration.

4 a useful application in other types of drives differing from the typesdescribedtabove.

While the invent-ion has been illustrated ,and described as embodied inwobble drives, it is not intended to be limited to the details shown,since various modifications and structural changes may be made withoutdeparting in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist ofthe present invention that others can by applying current knowledgereadily adapt itfor various apphcations without omitting features that,from the standpoint of prior art, fairly constitute essentialcharacteristics of the generic or specicaspects of this invention and,therefore, such adaptations should and are intendedrto be comprehendedwithin the meaning and range of equivalence of the following claims.

What :is claimed as new and desired to be secured by Letters Patent is:Y t

.1. A wobble drive for converting rotary motion into reciprocatinglinear motion comprising in combination, support means; a drive shaftsupported for rotation aboutits axis by said support means; a cup-shapedhead member iixed to said drive shaft for rotation therewith; a wobblespindle; bearing means supporting said wobble spindle and being freelyturnable about the axis ofsaid wobblespindle, said bearing means mountedwithin said Vcup-shaped headY memberY and connected thereto for turningmovement about an perpendicular to the axis of said drive shaft and theaxis of said wobble spindle; adjusting means operatively connected tosaid bearing means Yfor setting the angular position thereof withrespect to said axis perpendicular to said drive shaft and wobblespindlejaxes, said adjusting means including a nut to which said bearingmeans is connected for Yturning movement about another axisperpendicular to said drive shaft and wobble spindle axes and a screw.carried for turning movement about its axis by said head member and.extending threadedly through saidV nut, said screw being restrained bysaid head member against .'axial movementV so that when said screw isturned said nut Vshifts 'axially to tilt said bearing means with respectto said head member; a driven shaft'supported for reciprocation alongits ax-is by said support means; tool means fixed to said driven shaftfor reciprocation'therewith; a ball and` socket joint fixed to saiddriven shaft vand includingra ball member formed withra bore; and

lever meansrxed to said wobble spindle and having a `free end portionextending `slidably into said bore of said ball member. i

2. A wobble drive as recited in claim 1 and wherein said bearing meanshas a substantially spherical'con- References Cited in the tile of thispatent UNITED STATES PATENTS 1,222,391 Grant- Apr. l0, 1,917 1,679,884Thomas Aug. 7, 1928 1,901,981 Ousback Mar.,2l, 1933 2,246,689 Kost June24, 1941 2,247,527 lStinnes f July 1, 1941 2,824,455V

